Dispensing piston-cock for ice cream making machines

Abstract

A dispensing piston-cock for ice-cream machines comprises a baseplate and a cylinder, both made of plastic material. The cylinder is open at one end and has an ice-cream dispensing hole at the opposite end which is integral with the baseplate. A communication duct formed in the baseplate opens near the lower end of the cylinder and a piston is slidably mounted in the cylinder to reciprocate from a first position where it closes the communication duct and a second position at which the lower end of the piston is raised above the communication duct. The lower portion of the piston at least up to a height to cover the communication duct in the lower position of the piston is covered by a metal jacket.

I claim: 
     
       1. In a dispensing piston-cock for use in ice-cream machines having means for heating the ice-cream mix to a pasteurizing temperature, and means for refrigerating the ice-cream mix, and of the kind comprising a baseplate made of plastics material; a cylinder made of plastics material open at its upper end and provided with an ice-cream dispensing hole at its opposite or lower end; said cylinder being integral with or formed in said baseplate; at least one communication duct formed in said baseplate and opening in proximity of the lower end of said cylinder; a piston made of plastics material slidably mounted in said cylinder; at least two spaced sealing rings on the lower end portion of said piston; means for reciprocating said piston in said cylinder from a first position wherein it closes said communication duct with its lower end portion, to a second position wherein its lower end portion is lifted above said communication duct; the improvement according to which the said piston is covered at least over its lower end portionn by a metal jacket, which metal jacket extends up along the piston to a height above the communication duct so that the jacket covers the communication duct when the piston is in said first position at which it covers the communication duct, such that during the heating of the ice-cream mix the heat is conducted, by means of said metal jacket, to the interior walls of the cylinder. 
     
     
       2. A dispensing cock according to claim 1, in which the said metal jacket is provided with grooves accommodating the said spaced sealing rings. 
     
     
       3. A dispensing cock according to claim 1, in which said metal jacket is a copper jacket. 
     
     
       4. A dispensing cock according to claim 1, in which said metal jacket is an aluminum jacket. 
     
     
       5. A dispensing cock according to claim 1, in which the said metal jacket has a wall thickness of from 2 to 20 mm.